JP2016085452A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a transparent feeling.SOLUTION: A display device includes a pair of transparent substrates which are separately arranged to face each other, a light modulation layer which is arranged between a pair of transparent substrates and includes a plurality of light modulation elements which have predetermined refractive index anisotropy and are different in responsiveness to an electric field generated by an electrode provided in the transparent substrates, and a light source which makes light of a predetermined color incident on the light modulation layer from the side surface of the light modulation layer. The light modulation layer transmits incident light made incident from the light source, when the electric field is not generated and scatters the incident light and emits it to the transparent substrates, when the electric field is generated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a display device.

  In recent years, a display device or a lighting device using a polymer dispersed liquid crystal (PDLC) has been proposed. In such a display device or illumination device, the voltage applied to the PDLC can be controlled to switch between the transparent state and the scattering state.

  A typical normal PDLC is in a scattering state when the applied voltage is turned off, and is in a transparent state when the applied voltage is turned on. There is also a reverse PDLC that is in a transparent state when the applied voltage is turned off and in a scattering state when the applied voltage is turned on.

JP 2012-151081 A JP 2012-141588 A

  In one aspect, the present invention is to provide a display device with high transparency.

  One embodiment of the present invention is generated by a pair of transparent substrates that are spaced apart from each other and a pair of transparent substrates that have a predetermined refractive index anisotropy and are provided on the transparent substrate. A light modulation layer including a plurality of light modulation elements having different responsiveness to an electric field; and a light source that makes light of a predetermined color incident on the light modulation layer from a side surface of the light modulation layer. The display device transmits incident light from a light source when it is not generated, and scatters the incident light and emits it onto a transparent substrate when an electric field is generated.

It is the figure which showed an example of the structure of the display apparatus of 1st Embodiment. It is the figure which showed an example of the structure of the display apparatus of 2nd Embodiment. It is the figure which showed the structure of the display panel of 2nd Embodiment. It is a schematic diagram explaining the effect | action of the light modulation layer of 2nd Embodiment. It is the figure which showed the structure of the panel drive circuit of 2nd Embodiment. It is the figure which showed the structure of the side light source of 2nd Embodiment. It is the figure which showed the hardware constitutions of the display apparatus of 2nd Embodiment. It is the block diagram which showed the function structure of the display apparatus of 2nd Embodiment. It is a figure explaining an example of the synchronous drive control of 2nd Embodiment. It is the figure which showed the operation | movement timing of the field sequential control of 2nd Embodiment. It is the figure which showed the operation | movement timing of the line sequential control of 2nd Embodiment. It is the figure which showed an example of the structure which improves the straightness of incident light in 2nd Embodiment. It is the figure which showed the other example of the structure which improves the rectilinear advance property of incident light in 2nd Embodiment. It is the figure which showed the structural example which piled up the display panel of 3rd Embodiment in multiple numbers. It is the figure which showed an example of the structure of the display apparatus of 4th Embodiment. It is the figure which showed an example of the structure of the display apparatus of 5th Embodiment. It is the figure which showed an example of the injection | emission amount of the polarized light of 5th Embodiment. It is the figure which showed an example of the relationship between the transmittance | permeability by the polarization direction of the light which injected from the back surface of 5th Embodiment, and a drive voltage. It is the figure which showed an example of the display control of the display apparatus of 5th Embodiment. It is the figure which showed an example of the structure of the display apparatus of 6th Embodiment. It is the figure which showed an example of the structure of the display apparatus of 7th Embodiment. It is the figure which showed the 1st modification of the display apparatus of 7th Embodiment. It is the figure which showed the case where the projector light from which a polarization direction differs in the structure of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate changes while maintaining the gist of the invention are naturally included in the scope of the present invention. In addition, the drawings may be schematically represented with respect to the width, thickness, shape, and the like of each part in comparison with actual aspects for the sake of clarity of explanation, but are merely examples, and the interpretation of the present invention is not limited. It is not limited.
In the present invention and each drawing, the same reference numerals are given to the same elements as those described above with reference to the previous drawings, and the detailed description may be omitted as appropriate.

[First Embodiment]
A display device according to a first embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of the configuration of the display device according to the first embodiment. FIG. 1A is a plan view of the display device of the first embodiment. FIG. 1B is a cross-sectional view in the direction of arrows A1-A2 in FIG. 1A and 1B schematically show a display device, and are not necessarily the same as actual dimensions and shapes.

  As shown in FIG. 1A, in the display device 1 of the first embodiment, the outer surface of the transparent substrate 2 is open, and the plane of the transparent substrate 2 is visually recognized from the viewpoint of the observer. A light source 8 is disposed along one side of the plane of the transparent substrate 2. The plane of the light modulation layer 4 is formed below the plane of the transparent substrate 2. A planar area formed by the light modulation layer 4 is a display area.

  A configuration of the display device 1 will be described. As shown in FIG. 1B, the transparent substrate 2 includes a pair of transparent substrates 2a and 2b that are spaced apart from each other, and has a light modulation layer 4 between the transparent substrate 2a and the transparent substrate 2b. The outer surface opposite to the light modulation layer 4 side of the transparent substrates 2a and 2b is open. The light source 8 makes light incident on the light modulation layer 4 from the side surface of the light modulation layer 4.

  Here, the light modulation layer 4 includes a first light modulation element 4a and a second light modulation element 4b having a predetermined refractive index anisotropy. The first light modulation element 4a and the second light modulation element 4b have different responsiveness to the electric field generated by the electrodes provided on the transparent substrates 2a and 2b. For example, the response of the second light modulation element 4b to the electric field is relatively higher than the response of the first light modulation element 4a to the electric field.

  In such a light modulation layer 4, when no electric field is generated in the light modulation layer 4, the refractive index difference between the first light modulation element 4a and the second light modulation element 4b in all directions including the front direction and the oblique direction. There is almost no. For this reason, the incident light of the light source 8 incident from the side surface of the light modulation layer 4 is transmitted as it is, and is not emitted to the transparent substrates 2a and 2b side. Moreover, the light of the penetration direction which penetrates the layer which the transparent substrate 2a, the light modulation layer 4, and the transparent substrate 2b overlap is transmitted. Thus, the light modulation layer 4 has high transparency when no electric field is generated, and when the plane of the transparent substrate 2a is the front surface, the observer enters the transparent substrate 2b as the back surface from the outside. Light can be visually recognized. In the following description, the state in which the light modulation layer 4 transmits incident light is referred to as “transparent state”. The front direction indicates the direction in which the plane of the transparent substrate 2 is visually recognized, and the oblique direction indicates the other direction.

  On the other hand, when an electric field is generated in the light modulation layer 4, the refractive index difference corresponding to the difference in responsiveness between the first light modulation element 4a and the second light modulation element 4b increases in all directions. For this reason, incident light from the light source 8 is scattered in the light modulation layer 4, and the scattered light is emitted to the transparent substrates 2a and 2b. Therefore, the observer can visually recognize the scattered light emitted from the transparent substrate 2a. In the following description, a state in which the light modulation layer 4 scatters incident light is referred to as a “scattering state”.

  According to the display device 1 described above, by controlling the voltage application to the electrode that generates an electric field in the light modulation layer 4 and switching between generation and disappearance of the electric field generated in the light modulation layer 4, the light modulation layer 4 is made transparent. And the scattering state.

  In the display device 1, when no electric field is generated in the light modulation layer 4, there is almost no difference in refractive index between the first light modulation element 4a and the second light modulation element 4b in any direction. High transparency can be obtained. In general normal PDLC, although it is transparent in the front direction, it has a scattering property in an oblique direction, and thus the transparency is low. On the other hand, the display device 1 has high transparency in all directions. In addition, although the transparent substrate 2a side was demonstrated as the surface, it is the same also with the transparent substrate 2b as the surface.

  In addition, the display device 1 may be configured to divide the display area as indicated by a chain line in FIG. 1 and switch between the transparent state and the scattering state for each divided area. Thus, an image can be displayed by controlling the transparent state and the scattering state for each divided region. In the example of FIG. 1, an example in which the display area is divided into a matrix is shown, but the present invention is not limited to this. For example, the display area can be switched with one electrode, or the electrode can be arranged only in a part of the display area, and the generation and disappearance of the electric field can be switched only in the part of the area. You can also

Furthermore, although the display apparatus 1 was demonstrated as one Embodiment of this invention, this invention is not limited to this. For example, it is good also as an illuminating device which utilizes the light inject | emitted from the display apparatus 1 as illumination. Further, it is not always necessary for the display device 1 to perform display. For example, in a normal state, the transparent substrate 2 may be used as a transparent plate such as a window glass, and an image may be displayed as necessary. The display device 1 has high transparency in a state where no voltage is applied to the electrodes, and such use is also possible.
Hereinafter, a display device described as an embodiment is not a display device in a narrow sense but can be applied to various modes.

[Second Embodiment]
Next, a display device according to a second embodiment will be described. First, the configuration of the display device will be described.

(1) Configuration FIG. 2 is a diagram illustrating an example of the configuration of the display device according to the second embodiment.
The display device 10 illustrated in FIG. 2 includes a display panel 20, a panel drive circuit 30, a side light source 40, a light source drive circuit 50, an image output unit 60, and a synchronous drive unit 70. The display device 10 is an embodiment of the display device 1 shown in FIG. In the following, for the sake of convenience, when the display panel 20 is viewed from the front direction, the horizontal direction is the X direction, the vertical direction is the Y direction, and the depth direction is the Z direction.

  As shown in FIG. 1, the display panel 20 includes a pair of transparent substrates that are separated from each other with the light modulation layer interposed therebetween. The outer surface opposite to the light modulation layer side is open, and the observer can visually recognize the light emitted from the light modulation layer through the outer surfaces of the pair of transparent substrates. In addition, the display panel 20 shown in FIG. 2 shows a plane that is visible from the outside (the side opposite to the surface where the transparent substrate is in contact with the light modulation layer) with respect to the transparent substrate plane that sandwiches the light modulation layer. In the following description, an area where the light modulation layer emits light on this plane and allows the observer to visually recognize the color is referred to as a display area. The display panel 20 performs display control for each display unit, with a divided area obtained by dividing the display area as a display unit. In the following description, this display unit is referred to as a display cell Cpq. In the example of FIG. 2, the display cells Cpq are arranged in a two-dimensional matrix. Let p denote the position in the row direction and q denote the position in the column direction.

  The panel drive circuit 30 controls voltage application to the electrode that generates and disappears an electric field for each light modulation layer region corresponding to the display cell Cpq. In the panel drive circuit 30, a voltage is applied to the electrodes in units of display cells Cpq based on the drive signal input from the synchronous drive unit 70 to drive sequentially, and the scattering state and the transparent state of the light modulation layer region for each display cell Cpq. Switch between and.

The side light source 40 is disposed along the side of the display panel 20 and makes light of a predetermined color incident on the light modulation layer of the display panel 20. The side light source 40 emits different colors and has a plurality of color light sources that are controlled independently. For example, it includes a first color light source that emits a first primary color, a second color light source that emits a second primary color, and a third color light source that emits a third primary color. In the second embodiment, the first primary color is red, the second primary color is green, and the third primary color is blue. In addition, instead of the first primary color, the second primary color, and the third primary color, light sources of arbitrary colors having a complementary color relationship may be used in combination. Moreover, the apparatus which displays a single color may be sufficient.
The light source drive circuit 50 individually drives each light source of the side light source 40 based on the drive signal from the synchronous drive unit 70.

  The image output unit 60 outputs the image signal SRGB to the synchronous drive unit 70. In the image signal SRGB, color information corresponding to the display area of the display panel 20 is set. The image signal SRGB corresponds to, for example, the display cell Cpq, and includes a red component signal value Rpq, a green component signal value Gpq, and a blue component signal value Bpq. In the following description, in the image signal SRGB, it is assumed that the color information of the display cell Cpq is set for each display cell Cpq by the red component Rpq, the green component Gpq, and the blue component Bpq. Note that the image signal SRGB does not have to correspond one-to-one with the display cell Cpq.

  The synchronous driving unit 70 acquires the image signal SRGB and synchronously drives the panel driving circuit 30 and the light source driving circuit 50. Specifically, the driving of the electrodes by the panel driving circuit 30 with respect to the display cell Cpq and the light incidence from the side light source 40 by the light source driving circuit 50 are synchronized.

Details of each component will be described sequentially.
First, the display panel 20 will be described. FIG. 3 is a diagram illustrating a configuration of the display panel according to the second embodiment. FIG. 3A is a cross-sectional view of the display panel. FIG. 3B shows an example of the state of the light modulation layer when no voltage is applied. FIG. 3C illustrates an example of the state of the light modulation layer when a voltage is applied. 3B and 3C, the refractive index anisotropy of the light modulation element included in the light modulation layer is represented using a refractive index ellipsoid. This refractive index ellipsoid is a tensor ellipsoid representing the refractive index of linearly polarized light incident from various directions. By looking at the cross section of the ellipsoid from the light incident direction, the refractive index is geometrically It is something that can know.

  As shown in FIG. 3A, the display panel 20 is provided on the lower transparent substrate 22 and the upper transparent substrate 23 that are spaced apart from each other, and on the surface of the lower transparent substrate 22 that faces the upper transparent substrate 23. Light modulation disposed between the lower electrode 31 provided, the upper electrode 32 provided on the surface facing the lower transparent substrate 22 of the upper transparent substrate 23, and the lower transparent substrate 22 and the upper transparent substrate 23 Layer 80. Further, the side light source 40 is disposed at a position facing the light modulation layer 80 on the side surface of the display panel 20. The outer surfaces of the upper transparent substrate 23 and the lower transparent substrate 22 opposite to the light modulation layer 80 side are open and visible to the observer.

  The lower transparent substrate 22 and the upper transparent substrate 23 support the light modulation layer 80, and are generally configured by substrates that are transparent to visible light. Examples of such a substrate material include a glass plate and a resin substrate.

  The lower electrode 31 and the upper electrode 32 generate an electric field between the lower electrode 31 and the upper electrode 32 by applying a voltage, and an electric field is applied to the light modulation layer 80. The lower electrode 31 and the upper electrode 32 are both formed of a transparent material. The shapes of the lower electrode 31 and the upper electrode 32 differ depending on the driving method, but in any driving method, the electric field can be generated independently for each region corresponding to the display cell Cpq using the display cell Cpq as a driving unit. it can. The configuration of the lower electrode 31 and the upper electrode 32 will be described later.

  The light modulation layer 80 is a layer including two types of light modulation elements. The two types of light modulation elements have the same refractive index anisotropy and different responsiveness to an electric field. The display panel 20 shown in FIG. 3 is a composite layer that includes a liquid crystal monomer 81 and liquid crystal molecules 82 dispersed in the liquid crystal monomer 81. Here, the liquid crystal monomer 81 and the liquid crystal molecules 82 have the same ordinary light refractive index and extraordinary light refractive index. Note that, for example, a refractive index shift due to a manufacturing error is allowed. On the other hand, the responsiveness to the electric field is higher in the liquid crystal molecules 82 than in the liquid crystal monomers 81. The liquid crystalline monomer 81 has, for example, a streak structure or a porous structure that does not respond to an electric field, or a rod-shaped structure having a response speed slower than that of the liquid crystal molecules 82. The liquid crystal monomer 81 is an embodiment of the first light modulation element 4a, and the liquid crystal molecule 82 is an embodiment of the second light modulation element 4b. The liquid crystalline monomer 81 is preferably a monomer that can be polymerized by being cured by light or heat. When the liquid crystalline monomer 81 is polymerized to be polymerized, the liquid crystal molecules 82 and the liquid crystalline polymer (polymer material) are preferably cured while the ordinary light refractive index and the extraordinary light refractive index are equal to each other. Moreover, it is preferable that the liquid crystal molecule 82 has higher responsiveness to the electric field than the liquid crystal polymer. Hereinafter, the description about a liquid crystalline monomer is applicable also to the liquid crystalline polymer which polymerized the said liquid crystalline monomer. In addition, the light modulation layer 80 of this embodiment can be applied to a composite layer in which liquid crystal molecules 82 are dispersed in the polymer material, that is, a polymer dispersed liquid crystal (PDLC).

  For example, as shown in FIG. 3B, when no voltage is applied between the lower electrode 31 and the upper electrode 32 and no electric field is generated in the light modulation layer 80, the light of the liquid crystalline monomer 81a The direction of the axis AX1 and the direction of the optical axis AX2 of the liquid crystal molecules 82a are the same (parallel). The optical axes AX1 and AX2 indicate lines parallel to the traveling direction of the light beam so that the refractive index becomes one value regardless of the polarization direction. Note that the orientation of the optical axis AX1 and the orientation of the optical axis AX2 at this time may be slightly different due to, for example, a manufacturing error.

  On the other hand, as shown in FIG. 3C, when a voltage is applied between the lower electrode 31 and the upper electrode 32 and an electric field is generated in the light modulation layer 80, the optical axis AX1 of the liquid crystalline monomer 81b The direction and the direction of the optical axis AX2 of the liquid crystal molecules 82b intersect each other.

  The operation of such a light modulation layer 80 will be described. FIG. 4 is a schematic diagram for explaining the operation of the light modulation layer of the second embodiment. FIG. 4A is a schematic diagram illustrating the operation of the light modulation layer when no voltage is applied, and FIG. 4B is a schematic diagram illustrating the operation of the light modulation layer when voltage is applied.

  In the state where no voltage is applied in FIG. 4A, no voltage is applied between the upper electrode 32 and the lower electrode 31, and no electric field is generated in the light modulation layer 80. In this state, as shown in FIG. 3B, the directions of the optical axis AX1 of the liquid crystal monomer 81a and the optical axis AX2 of the liquid crystal molecules 82a coincide with each other, and are refracted in all directions including the front direction and the oblique direction. There is almost no difference in rate. For this reason, for example, the incident lights L11, L12, and L13 of the side light source 40 incident from the side surface indicated by the chain line pass through the light modulation layer 80 without being scattered in the light modulation layer 80. The light traveling from the side light source 40 toward the lower transparent substrate 22 or the upper transparent substrate 23 is totally reflected and is not emitted outside. Further, the light L21 and L22 incident in the penetrating direction penetrating the lower transparent substrate 22, the light modulation layer 80, and the upper transparent substrate 23 from the outside of the lower transparent substrate 22 indicated by the alternate long and short dash line within the light modulation layer 80. The light passes through the light modulation layer 80 without being scattered and is emitted from the upper transparent substrate 23. Thus, when no voltage is applied between the lower electrode 31 and the upper electrode 32, the light modulation layer 80 has high transparency.

  On the other hand, in the state of voltage application in FIG. 4B, a voltage is applied between the upper electrode 32 and the lower electrode 31, and an electric field is generated in the light modulation layer 80. In this state, as shown in FIG. 3C, the direction of the optical axis AX1 of the liquid crystalline monomer 81b intersects the direction of the optical axis AX2 of the liquid crystal molecules 82b, and any direction including the front direction and the oblique direction. Since the refractive index difference becomes large, a high scattering property can be obtained. For example, incident light L 11, L 12, L 13 of the side light source 40 incident from the side surface is scattered in the light modulation layer 80, and the scattered light L 31, L 32 is emitted from the upper transparent substrate 23. Thereby, when the upper transparent substrate 23 is observed from the upper direction of FIG. 4B, the scattered lights L31 and L32 can be visually recognized. The same applies to the case where the lower transparent substrate 22 is observed from the lower direction in FIG.

  In the display device 10 having such a configuration, when the upper transparent substrate 23 or the lower transparent substrate 22 is viewed from the front, the light transmitted through the penetrating direction is visually recognized when no voltage is applied. On the other hand, in a voltage application state, incident light from the side light source 40 scattered and emitted from the light modulation layer 80 is visually recognized.

Next, the panel drive circuit 30 will be described. FIG. 5 is a diagram illustrating the configuration of the panel drive circuit according to the second embodiment.
The panel drive circuit 30 is connected to the plurality of strip-like lower electrodes 31 and the plurality of upper electrodes 32, and selectively drives the lower electrode 31 and the upper electrode 32 to thereby generate an electric field corresponding to the display cell Cpq. Control the occurrence and disappearance of

  The lower electrode 31 is a transparent electrode provided on the lower transparent substrate 22 and has a strip shape extending in one direction within the surface of the lower transparent substrate 22. The upper electrode 32 is a transparent electrode provided on the upper transparent substrate 23, and has a strip shape extending in one direction within the plane and in a direction intersecting with the extending direction of the lower electrode 31. A portion where the lower electrode 31 and the upper electrode 32 intersect is a region corresponding to the display cell Cpq. The extending direction of the lower electrode 31 and the extending direction of the upper electrode 32 may be orthogonal to each other.

  The panel drive circuit 30 performs simple matrix drive control for sequentially driving the plurality of lower electrodes 31 and the plurality of upper electrodes 32. By employing simple matrix driving, it is not necessary to provide wiring or the like in the plane of the display panel 20, and higher transparency can be obtained.

  It is also possible to form one electrode with a solid film (that is, do not form after film formation) and to drive each of the electrodes in an active matrix with the other electrode having a small square shape. Various driving formats for driving the light modulation layer 80 in units of the display cell Cpq are known. The panel driving circuit 30 appropriately uses such a driving format according to the use of the display device 10 or the like. Can be configured.

Next, the side light source 40 will be described. FIG. 6 is a diagram illustrating a configuration of a side light source according to the second embodiment.
The side light source 40 has a configuration in which light source units 41, 42, 43, 44, 45, and 46 are sequentially arranged along one direction of the display area of the display panel 20, and is connected to a light source driving circuit 50 that drives each light source. Connecting.

  The light source unit 41 includes a red light source 41R that emits red light, a green light source 41G that emits green light, and a blue light source 41B that emits blue light. The red light source 41R, the green light source 41G, and the blue light source 41B can be connected to the light source driving circuit 50 and driven independently. The other light source units 42, 43, 44, 45, 46 have the same configuration. Unless otherwise specified and described, the light sources of the respective colors constituting the light source unit are represented as a red light source 4nR, a green light source 4nG, and a blue light source 4nB.

  The light source drive circuit 50 drives the red light source 4nR, the green light source 4nG, and the blue light source 4nB, respectively, based on the drive signal from the synchronous drive unit 70. For example, by turning on the red light source 41 </ b> R of the light source unit 41, red light is incident on the region of the light modulation layer 80 corresponding to the display cell row arranged at the left end of the display panel 20. Similarly, light of each color is incident on the green light source 41G and the blue light source 41B. The light source driving circuit 50 can sequentially emit incident light of each color into the light modulation layer 80 in synchronization with the panel driving circuit 30 to display a desired color in units of display cells Cpq. Moreover, not only each of the red light source 4nR, the green light source 4nG, and the blue light source 4nB is lit in a single color, but a plurality of colors may be lit simultaneously. For example, if the red light source 4nR and the blue light source 4nB are turned on simultaneously, magenta light can be incident on the display panel 20. Similarly, the red light source 4nR, the green light source 4nG, and the blue light source 4nB may all be turned on and white light may be incident. Further, for example, when performing monochromatic display or the like, light of a desired color may be formed by combining the lighting time and light emission intensity of each light source, and incident on the light modulation layer 80.

  In the example of FIG. 6, one light source unit is arranged for one display cell column, but a plurality of light source units may be arranged for one display cell column. Moreover, although the red light source 4nR, the green light source 4nG, and the blue light source 4nB are arranged in the extending direction of the side light source 40, for example, they may be arranged in a direction perpendicular to the extending direction of the side light source 40. . The arrangement form of each light source is not limited as long as light of the three primary colors can be incident on the display cell column.

Next, a hardware configuration will be described. FIG. 7 is a diagram illustrating a hardware configuration of the display device according to the second embodiment.
The entire display device 10 is controlled by the control unit 90. The control unit 90 includes a CPU (Central Processing Unit) 91, and a RAM (Random Access Memory) 92 and a ROM (Read Only Memory) 93 and a plurality of peripheral devices are connected to the CPU 91 via a bus 96. .

The CPU 91 is a processor that implements the processing function of the control unit 90.
The RAM 92 is used as a main storage device of the control unit 90. The RAM 92 temporarily stores at least part of an OS (Operating System) program and application programs to be executed by the CPU 91. The RAM 92 stores various data necessary for processing by the CPU 91.

  The ROM 93 is a read-only semiconductor storage device that stores an OS program, application programs, and fixed data that is not rewritten. Further, instead of the ROM 93 or in addition to the ROM 93, a semiconductor storage device such as a flash memory can be used as a secondary storage device.

Peripheral devices connected to the bus 96 include a panel drive circuit 30, a light source drive circuit 50, an input interface 94, and a communication interface 95.
A display panel 20 is connected to the panel drive circuit 30.
A side light source 40 is connected to the light source driving circuit 50.

The input interface 94 is connected to an input device for inputting a user instruction and an interface for acquiring an image signal from another device. The input interface 94 transmits a signal sent from the input device or another device to the CPU 91.
The communication interface 95 is connected to the network 98. The communication interface 95 transmits / receives data to / from another computer or communication device via the network 98.

With the hardware configuration as described above, the processing functions of this embodiment can be realized. The above configuration is an example, and the configuration is changed as appropriate.
Note that the processing functions of the image output unit 60 and the synchronous drive unit 70 illustrated in FIG.

Next, a functional configuration included in the display device 10 will be described. FIG. 8 is a block diagram illustrating a functional configuration of the display device according to the second embodiment.
The display device 10 includes a synchronous drive unit 70 that synchronously drives the panel drive circuit 30 and the light source drive circuit 50 based on the image signal SRGB input from the image output unit 60. The synchronization drive unit 70 includes a timing generation unit 71 that generates a synchronization signal STM, a display cell drive signal generation unit 72, and a light source drive signal generation unit 73.

Processing of each part of the synchronous drive unit 70 will be described.
The timing generator 71 generates a synchronization signal STM for synchronizing operation timings of the panel drive circuit 30 and the light source drive circuit 50. The generated synchronization signal STM is output to the panel drive circuit 30 and the light source drive circuit 50.

  The display cell drive signal generator 72 generates a display cell drive signal SCEL for driving the electrode corresponding to the display cell Cpq based on the image signal SRGB, and outputs it to the panel drive circuit 30 together with the synchronization signal STM. In the display cell driving signal SCEL, driving values corresponding to the red component Rpq, the green component Gpq, and the blue component Bpq included in the image signal SRGB are set.

  The light source drive signal generation unit 73 generates a light source drive signal LRGB for driving the red light source 4nR, the green light source 4nG, and the blue light source 4nB corresponding to the display cell Cpq based on the image signal SRGB, and outputs the light source drive signal LRGB to the light source drive circuit 50.

  The panel drive circuit 30 and the light source drive circuit 50 are synchronously driven by a synchronization signal STM. For example, in synchronization with the light source drive circuit 50 lighting the red light source 4nR based on the light source drive signal LRGB, the panel drive circuit 30 generates a voltage corresponding to the red component Rpq of the target display cell Cpq of the display cell drive signal SCEL. Applied to the electrode of the target display cell Cpq. Thereby, red scattered light corresponding to the luminance of the red light source 4nR incident by the light source driving circuit 50 and the voltage applied to the electrodes by the panel driving circuit 30 is emitted from the target display cell Cpq. The same applies to other colors.

As described above, the panel drive circuit 30 and the light source drive circuit 50 are synchronously driven to reproduce the display of the red component Rpq, the green component Gpq, and the blue component Bpq of the image signal SRGB in the display cell Cpq.
In the synchronous drive unit 70, in order to reproduce each color component, the light emission time or light emission intensity (luminance) of the red light source 4nR, the green light source 4nG, and the blue light source 4nB and the voltage application time or the voltage based on the image signal SRGB The magnitude of the voltage is appropriately determined.

(2) Display Function Next, function processing of the display device 10 having the above configuration will be described with reference to FIG.
FIG. 9 is a diagram illustrating an example of synchronous drive control according to the second embodiment. In FIG. 9, the synchronous drive unit 70 is omitted.

  The panel drive circuit 30 performs simple matrix control in which a voltage is sequentially applied to electrodes that generate an electric field in the light modulation layer 80 corresponding to the display cell Cpq. In the panel drive circuit 30, in one image display frame for displaying an image based on the image signal SRGB on the display panel 20, the side light source 40 supplies the red light source 4nR, the green light source 4nG, and the blue light source 4nB to one display cell Cpq, respectively. Control is performed to apply a voltage to the electrode three times in total when it is lit. Thereby, the light of the red component Rpq, the green component Gpq, and the blue component Bpq based on the image signal SRGB is sequentially emitted from the light modulation layer 80 for one display cell Cpq, and the observer visually recognizes the color corresponding to the image signal SRGB. be able to. When all the color components of the image signal SRGB are 0, the electrode corresponding to the display cell Cpq is not driven, and the observer visually recognizes the transparent state of the display cell Cpq.

  For example, as shown in FIG. 9, it is assumed that the light source unit 45 of the side light source 40 lights the green light source 45G by the light source drive circuit 50 that receives the synchronization signal STM and the light source drive signal LRGB. Thereby, the light source incident light L14 of the green light source 45G enters the light modulation layer region corresponding to the display cell C25. The panel drive circuit 30 applies a voltage to the electrode corresponding to the display cell C25 when the light source incident light L14 is incident on the light modulation layer region of the display cell C25 based on the synchronization signal STM. The magnitude or application time of the voltage to be applied is determined by the display cell drive signal generator 72 according to the light intensity of the light source incident light L14 and the green component G25 of the display cell C25. By applying a voltage to the corresponding electrode, the light modulation layer region corresponding to the display cell C25 is in a scattering state, the scattered light L31 of the light source incident light L14 is emitted, and the observer can visually recognize green. Similar processing is performed for other display cells Cpq. Further, the same processing is performed on the red component Rpq and the blue component Bpq for all the display cells Cpq, and one image display frame cycle is completed.

  In this way, the voltage application to the electrodes in the panel drive circuit 30 and the driving of the side light source 40 by the light source drive circuit 50 are performed in synchronization for each color component by the synchronous drive unit 70, and the image signal is transmitted to the display cell Cpq. A color based on SRGB is displayed.

  In the above description, the color components included in the image signal SRGB are the red component Rpq, the green component Gpq, and the blue component Bpq, and the lighting of the corresponding red light source 4nR, green light source 4nG, and blue light source 4nB is synchronized with the driving of the electrodes. However, the present invention is not limited to this. For example, the color components may be cyan, magenta, and yellow, and the green light source 4nG and the blue light source 4nB, the red light source 4nR and the blue light source 4nB, and the red light source 4nR and the green light source 4nG may be turned on during each drive period. In addition, a color light source provided in the side light source 40, a combination of colors that are turned on during driving, and the like can be appropriately selected in accordance with a desired display.

  In addition, a configuration and a driving method for driving in synchronization with voltage application to the electrodes by the panel driving circuit 30 and driving of the side light source 40 by the light source driving circuit 50 are appropriately determined. Hereinafter, field sequential control and line sequential control will be described as an example. In the following description, the process of sequentially applying a voltage to the electrodes corresponding to the display cells Cpq in a predetermined order is referred to as scanning.

  The field sequential control is a control for controlling the color switching of the side light source 40 for each display area (field) and scanning the display cell Cpq in synchronization with this. On the other hand, the line sequential control is a control for switching the lighting color of the side light source 40 for each block of the side light source 40 or a block composed of a plurality of columns and scanning the display cell Cpq in synchronization with this.

  First, field sequential control will be described. FIG. 10 is a diagram illustrating the operation timing of the field sequential control according to the second embodiment. Rpq, Gpq, and Bpq in FIG. 10 indicate that the corresponding display cells Cpq display red (R), green (G), and blue (B), respectively. Similarly, R, G, and B corresponding to the light source units indicate that each light source unit lights the red light source 4nR, the green light source 4nG, and the blue light source 4nB, respectively.

  In the field sequential control, as shown in FIG. 10, the same color light sources of the side light sources 40 are turned on all at once, and all display cells Cpq in the display area are scanned. Repeat the switching procedure.

  In the example of FIG. 10, the panel drive circuit 30 includes display cells Cpq for each row in the order of drive lines for display cells C11 to C19, drive lines for display cells C21 to C29,..., Drive lines for display cells C51 to C59. Scan. The light incident direction of the side light source 40 incident in the Y direction of the display panel 20 shown in FIG. 9 is different from the scanning direction of the display cell Cpq which is the X direction.

  In the field sequential control, the lighting color of the side light source 40 is switched in units of fields. Therefore, in the example of FIG. 10, the period from the first display cell C11 to the last display cell C59 is driven in the first scan. The light source units 41-49 all turn on the red light sources 41R-49R. The panel drive circuit 30 sequentially drives the electrodes corresponding to the display cells Cpq based on the display cell drive signal SCEL acquired from the display cell drive signal generation unit 72. Thereby, each display cell Cpq displays the red component Rpq of the image signal SRGB.

  In synchronization with the timing when the scanning of the last red display cell C59 is completed, the light source driving circuit 50 switches the light source to be lit for the light source unit 41-49 from the red light source 41R-49R to the green light source 41G-49G. In the second scan, all of the light source units 41-49 turn on the green light source 40G, and the panel drive circuit 30 sequentially drives the electrodes corresponding to the display cells Cpq based on the display cell drive signal SCEL. Thereby, each display cell Cpq displays the green component Gpq of the image signal SRGB.

  The light source drive circuit 50 switches the light source of the light source unit 41-49 from the green light source 41G-49G to the blue light source 41B-49B in synchronization with the timing when the scanning of the last green display cell C59 is completed. In the third scan, all the light source units 41-49 turn on the blue light sources 41B-49B, and the display cell Cpq displays the blue component Bpq of the image signal SRGB by the scan of the panel drive circuit 30.

  Thus, the red component Rpq, the green component Gpq, and the blue component Bpq are sequentially displayed, and an image based on the image signal SRGB is displayed on the display panel 20. In FIG. 10, the display cell Cpq is scanned in the X direction, but it may be scanned in the Y direction. Further, the order of the incident colors may be different from the above order.

  Next, line sequential control will be described. FIG. 11 is a diagram illustrating the operation timing of the line sequential control according to the second embodiment. The symbols shown in FIG. 11 are the same as those in FIG.

  In the example shown in FIG. 11, the light source driving circuit 50 drives the light sources of the respective colors in the order of the light source units 41, 42, 43, 44, 45, 46, 47, 48, 49. The panel drive circuit 30 scans in units of a group of display cells Cpq that correspond to the light sources of the respective colors and are arranged along the incident direction in which light from the light sources travels through the light modulation layer 80. Specifically, the panel drive circuit 30 corresponds to the drive lines of the display cells C11 to C51 corresponding to the light source unit 41, the drive lines of the display cells C12 to C52 corresponding to the light source unit 42,. The display cells Cpq are scanned for each column in the order of the drive lines of the display cells C19 to C59. As described above, in the control shown in FIG. 11, the light incident direction of the side light source 40 incident in the Y direction of the display panel 20 shown in FIG. 9 is the same as the scan direction (Y direction) of the display cell Cpq. .

  In the example of FIG. 11, the light source drive circuit 50 turns on the red light source 41 </ b> R for the light source unit 41 in the first scan. The panel drive circuit 30 scans the corresponding display cells C11-C51 in the first column and displays red components R11-R51. Subsequently, the light source driving circuit 50 turns on the red light source 42R of the adjacent light source unit 42, and the panel driving circuit 30 scans the corresponding display cells C12-C52 in the second column to display the red component R12-R52. To do. Thereafter, the same processing is repeated for each column, and the light source driving circuit 50 drives the red light source 49R of the light source unit 49. The panel drive circuit 30 scans the corresponding display cells C19 to C59 in the ninth column and displays red components R19 to R59.

  In the second scan, the lighting source of the light source unit 41 is switched from the red light source 41R to the green light source 41G. The panel drive circuit 30 scans the corresponding display cells C11-C51 in the first column and displays green components G11-G51. Thereafter, the same processing is repeated for each column to display the green components G19 to G59.

  In the third scan, the light source driving circuit 50 switches the lighting light source of the light source unit 41 from the green light source 41G to the blue light source 41B. The panel drive circuit 30 scans the corresponding display cells C11-C51 in the first column and displays the blue components B11-B51. Thereafter, the same processing is repeated for each column, and the blue components B19 to B59 are displayed.

  Thus, the red component Rpq, the green component Gpq, and the blue component Bpq are sequentially displayed, and an image based on the image signal SRGB is displayed on the display panel 20. In FIG. 11, the side light source 40 is controlled in units of light source units. However, this processing may be performed in units of blocks in which several light source units are combined.

In the example illustrated in FIG. 11, for example, the light source unit 41 is lit with the red (R) light source during a period after the red (R) light source of the light source unit 41 is turned on and the display cells C11 to C51 are scanned. Although the state is maintained, it may be turned off. The incident light of the red (R) light source is required from the light source unit 41 during the period during which the corresponding display cells C11 to C51 are scanned, so that it may be controlled to light only during this period. The same applies to other colors and other display cells Cpq.
By performing control in this way, the power consumption of the side light source 40 can be reduced.

  In addition to field sequential control and line sequential control, for example, a multiline driving method (Multiline Selection) for simultaneously selecting a plurality of scanning electrodes known in a simple matrix type liquid crystal panel may be used.

  As described above, in the display device 10, the scanning of the display cells Cpq by the panel driving circuit 30 and the switching of the colors of the side light sources 40 by the light source driving circuit 50 are performed in synchronization by the synchronous driving unit 70. As a result, incident light incident from the side light source 40 on the light modulation layer 80 corresponding to the display cell Cpq is scattered according to the magnitude of the voltage when a voltage is applied to the electrode, and no voltage is applied. Is transparent. That is, in the display device 10, the display cell Cpq in which no voltage is applied to the electrodes is visually recognized in a transparent state, and the display cell Cpq in which a voltage is applied to the electrodes is visually recognized in a scattered state. In particular, in the display device 10 of the second embodiment, the liquid crystal monomer 81 and the liquid crystal molecules 82 included in the light modulation layer 80 have almost no difference in refractive index in a state where no voltage is applied to the electrodes, and high transparency. Can be obtained.

  Since such a display device 10 can obtain high transparency in a state where no voltage is applied to the electrodes, it can be applied to a field that is difficult to use in the conventional normal PDLC. For example, when the state in which the electrodes of the entire display cell Cpq of the display panel 20 are turned off is normal, the display panel 20 is normally in a transparent state, and the display panel 20 is based on the image signal SRGB when display is required. It can be used to display images. In a normal transparent state, since the viewer can visually recognize what is placed on the back, a mirror, a blackboard, or the like may be placed. In a normal state, an observer can view and use a mirror or blackboard, but can display information on a mirror or blackboard when necessary.

(3) Modification Next, a modification of the second embodiment will be described.
In the line sequential control shown in FIG. 11, light sources of a plurality of colors are simultaneously incident on the light modulation layer 80. For example, when an LED (Light Emitting Diode) is used as the light source, light having a relatively high directivity is incident, but the color of the incident light may be mixed at a color boundary where colors are different between adjacent light source units. There is. For clear display, it is preferable to prevent color mixing of incident light.

  Therefore, the synchronous drive unit 70 controls the drive of the panel drive circuit 30 and the light source drive circuit 50 so that no color mixing of incident light occurs. Specifically, the synchronous drive unit 70 is in a state where light of the same color light source is incident on a column of display cells Cpq adjacent to the column of display cells Cpq to be driven, or in a state where no light is incident. Drive control is performed as follows.

  For example, the display cell Cpq is divided into sub-blocks parallel to the light incident direction of the side light source 40, and interlaced driving is performed. Note that the color of the incident light is the same in the sub-block. For example, the display cells Cpq shown in FIG. 9 are alternately scanned every sub-block, and the light source units corresponding to the display cells Cpq of the non-target sub-block are turned off. Thereby, the incident light incident on the display cell Cpq of the driven sub-block does not mix colors.

  Further, when switching the color of the light source in each light source unit, a non-lighting period of the light source may be provided. For example, the non-lighting time is provided in the period during which the display cells C11 to C51 are scanned before the lighting light source of the light source unit 42 shown in FIG. 11 is switched from the red light source 42R to the green light source 42G. In the scanning period of the display cells C11-C51, the adjacent light source units 42 are not lit, so that light incident on the display cells C11-C51 does not mix colors. In the scanning period of the display cells C12 to C52 in the next row, the adjacent light source unit 41 side is lit, but since the light source of the same color as the light source unit 42 is lit, no color mixing occurs. The light source unit 43 adjacent to the other is not lit and does not affect the scanning of the display cells C12 to C52.

  In this way, mixing of incident light can be prevented by controlling the synchronous driving unit 70. Further, for example, it is possible to provide a configuration that physically increases the straightness of light and prevents adjacent light from being mixed. Such a configuration will be described with reference to FIGS.

  FIG. 12 is a diagram illustrating an example of a configuration that improves the straightness of incident light in the second embodiment. FIG. 12 shows a configuration that includes an incident light diffusion prevention unit that prevents diffusion of light emitted from the side light source 40 that enters the light modulation layer 80 between the side light source 40 and the display panel 20 in order to improve the straightness of incident light. It is. As an example of the incident light diffusion prevention unit, a high aspect pattern 401 or a lens 402 is disposed.

  The high aspect pattern 401 has a resist pattern with a high aspect ratio, and has a shape in which light paths are provided in a lattice shape or a honeycomb shape, for example. A high aspect pattern 401a illustrated in FIG. 12 is a perspective view illustrating an example of a high aspect pattern 401 having a lattice shape. By passing through the high aspect pattern 401 disposed in the path of incident light between the side light source 40 and the display panel 20, the spread of incident light is suppressed.

  The lens 402 has a function of converging incident light incident on the lens 402 from the side light source 40, and emits the converged incident light to the light modulation layer 80, thereby improving the straightness of the incident light.

  FIG. 13 is a diagram showing another example of a configuration that improves the straightness of incident light in the second embodiment. In the configuration shown in FIG. 12, the incident light diffusion prevention unit is provided between the side light source 40 and the display panel 20, but in FIG. 13, the in-layer light diffusion prevention unit that prevents the spread of incident light in the light modulation layer 80. Is provided. In FIG. 13, the light modulation layer 80 between the lower transparent substrate 22 and the upper transparent substrate 23 is omitted.

  In order to improve the rectilinearity of the light incident on the light modulation layer 80, an in-layer light diffusion preventing portion is provided on the lower transparent substrate 22 and the upper transparent substrate 23 along the direction in which the incident light travels. In the example of FIG. 13, the light guide pattern 24 is provided on the light modulation layer 80 side of the lower transparent substrate 22 of the display panel 20. A cylindrical pattern 25 is provided on the side of the upper transparent substrate 23 opposite to the light modulation layer 80. The light guide pattern 24 and the cylindrical pattern 25 may be provided together, or only one of them may be provided.

  The light guide pattern 24 is provided between the adjacent display cells Cpq, for example, between the strip electrodes corresponding to the adjacent display cells Cpq. The light spread to the light guide pattern 24 side is reflected by the light guide pattern 24 and returned to the center side. Thereby, the incident light that has entered the light modulation layer 80 can travel straight in the path provided by the light guide pattern 24.

  The cylindrical pattern 25 is formed by forming a cylindrical lens as a pattern on the upper transparent substrate 23, and has a function of collecting incident light on a straight line in the extending direction of the cylindrical pattern 25. Thereby, the spread of the incident light that has entered the light modulation layer 80 can be suppressed, and straightness can be improved.

Further, as the light source of the side light source 40, laser light with high straightness may be used.
Thus, a clear image free from color mixture can also be obtained by physically increasing the straightness of incident light.

[Third Embodiment]
Next, a configuration in which a plurality of display panels 20 according to the second embodiment are stacked will be described as a third embodiment.
The display device 10 described above has a single display panel 20. However, since the display panel 20 has high transparency as described above, even if a plurality of display panels 20 are stacked, display is performed from an observer. A display similar to the configuration of one panel 20 can be visually recognized.

  FIG. 14 is a diagram illustrating a configuration example in which a plurality of display panels according to the third embodiment are stacked. The same components as those of the display device 10 shown in FIG.

  The display device 100 includes an image output unit 60, a synchronous drive unit 170, three-layer display panels 20R, 20G, and 20B, panel drive circuits 30R, 30G, and 30B corresponding to the display panels 20R, 20G, and 20B, and a side The light sources 40R, 40G, and 40B and the light source drive circuits 50R, 50G, and 50B corresponding to the side light sources 40R, 40G, and 40B are included. In FIG. 14, the positions of the display panels 20 </ b> R, 20 </ b> G, and 20 </ b> B are illustrated with being shifted for the sake of explanation, but the respective display areas overlap.

  The display panels 20R, 20G, and 20B and the panel drive circuits 30R, 30G, and 30B are the same as the display panel 20 and the panel drive circuit 30 shown in FIG.

  The side light sources 40R, 40G, and 40B include the red light source 4nR, the green light source 4nG, and the blue light source 4nB, respectively, whereas the light source units 41 to 49 of the side light source 40 illustrated in FIG. , 20B enter monochromatic light. The side light source 40R includes only a red light source, the side light source 40G includes only a green light source, and the side light source 40B includes only a blue light source. The light source drive circuits 50R, 50G, and 50B are the same as the light source drive circuit 50 shown in FIG.

  According to such a configuration, the display panel 20R displays the red component Rpq on the display cell Cpq of the display panel 20R according to the incident light from the side light source 40R. The display panel 20G displays the green component Gpq in the display cell Cpq of the display panel 20G according to the incident light from the side light source 40G. Then, the display panel 20B displays the blue component Bpq on the display cell Cpq of the display panel 20B according to the incident light from the side light source 40B. By overlapping the display panels 20R, 20G, and 20B, the observer can visually recognize the display based on the image signal SRGB.

  As described above, in a transparent state where no voltage is applied to the electrode corresponding to the display cell Cpq, the display cell Cpq can emit light incident from the back surface. For example, the light emitted from the display panel 20B can be viewed by an observer if the display cells Cpq corresponding to the display panel 20G and the display panel 20R are in a transparent state.

  Therefore, the synchronous drive unit 170 controls the panel drive circuits 30R, 30G, and 30B and the light source drive circuits 50R, 50G, and 50B so that the scan lines of the display panels 20R, 20G, and 20B are different from each other. The synchronization drive unit 170 generates a synchronization signal STM, a display cell drive signal SCEL, and a light source drive signal LRGB based on the image signal SRGB input from the image output unit 60. The display cell drive signal SCEL and the light source drive signal LRGB are separated for each color component and are output to the corresponding color panel drive circuits 30R, 30B, 30G and the light source drive circuits 50R, 50G, 50B. The panel drive circuits 30R, 30B, and 30G are determined in advance so that the lines to start scanning are different, and the synchronous drive unit 170 adjusts the control signal in accordance with the lines to be started.

  For example, when the panel drive circuits 30R, 30G, and 30B select the rows of the display panels 20R, 20G, and 20B and sequentially scan the display cells Cpq in the row direction (horizontal direction), the respective start rows are changed. Shift. The panel drive circuit 30R starts scanning from the first row, the panel drive circuit 30G starts from the second row, and the panel drive circuit 30B starts scanning from the third row. The panel drive circuits 30R, 30G, and 30B scan in synchronization. I do. Since the rows to be scanned are shifted in the display panels 20R, 20G, and 20B, for example, light emitted from the lower display panel 20G is transmitted through the upper display panel 20R in which no voltage is applied to the corresponding row electrode. And visually recognized by an observer. Similarly, light emitted from the lower display panel 20B passes through the upper display panels 20G and 20R and is visually recognized.

According to such a configuration, the number of colors of each color light source arranged in the side light source 40 per one display panel 20 can be reduced, so that the display cell Cpq is compared with the case where there is one display panel 20. Can be made smaller. Further, each panel drive circuit 30R, 30G, 30B only needs to scan each color, and therefore, detailed display is possible as compared with the case where it is constituted by a single display panel 20. Further, if the size of the display cell Cpq is the same as that in the case where the display panel 20 is one, the image can be updated at a higher speed.
In the above configuration, three display panels 20 are stacked, but the present invention is not limited to this. For example, two display panels 20 may be stacked, one for red display and the other for blue and green display. Further, four display panels 20 may be stacked, and for example, in addition to displaying red, green, and blue, a display panel 20 that displays white may be further added. Of course, a plurality of display panels 20 from which the side light source 40 emits the same color may be stacked.

[Fourth Embodiment]
Next, a fourth embodiment will be described.
Although the light source is a side light source in the second embodiment, the fourth embodiment has a configuration in which the light source is an external light source.
FIG. 15 is a diagram illustrating an example of a configuration of a display device according to the fourth embodiment. The same components as those of the display device 10 shown in FIG.

The display device 200 includes a display panel 20, a panel drive circuit 30, an image output unit 60, an external light source 240, an external light source drive unit 250, and a synchronous drive unit 270.
The display panel 20, the panel drive circuit 30, and the image output unit 60 have the same configuration as the number shown in FIG.

  The external light source 240 includes a red external light source 240R that emits red light, a green external light source 240G that emits green light, and a blue external light source 240B that emits blue light. The light of each color is emitted toward the display panel 20. As with the side light source 40, the color of each color light source of the external light source 240 is arbitrary. Further, the external light source 240 may be disposed anywhere as long as light can be incident on the display panel 20.

The external light source drive unit 250 acquires the synchronization signal STM and the light source drive signal LRGB from the synchronization drive unit 270 and drives the external light source 240.
The synchronization drive unit 270 acquires the image signal SRGB from the image output unit 60, and synchronizes the scan timing of the display cell Cpq by the panel drive circuit 30 with the drive timing of the external light source 240 by the external light source drive unit 250. And a display cell drive signal SCEL and a light source drive signal LRGB. As the synchronization signal STM, the display cell drive signal SCEL, and the light source drive signal LRGB, signals similar to those shown in FIG. 8 are generated.

  In the display device 200 having such a configuration, for example, display by field sequential control will be described. The external light source driving unit 250 switches the output light source of the external light source 240 every time the panel driving circuit 30 scans the display cell Cpq of the display panel 20. At the timing when the external light source driving unit 250 drives the red external light source 240R, the panel drive circuit 30 scans the display cell Cpq based on the red component Rpq. The same applies to other colors. Incident light from the external light source 240 is scattered by the light modulation layer region of the display cell Cpq and emitted from the display panel 20 when a voltage is applied to the electrode of the display cell Cpq. When no voltage is applied to the electrode of the display cell Cpq, the incident light of the external light source 240 is transmitted through the light modulation layer 80. Thereby, the observer can visually recognize the transparent state of the display cell Cpq.

  As described above, even when the light source changes from the side light source 40 to the external light source 240, the synchronous driving unit 270 can display an image on the display panel 20 in the same manner as in the case of the side light source 40. In other words, the synchronous drive unit 270 controls the external light source drive unit 250 and the panel drive circuit 30 to apply a voltage to the corresponding electrode and the timing at which light is incident from the external light source 240 for the target display cell Cpq. Display is performed by synchronizing the timing.

Further, since the side light source 40 and the external light source 240 can be handled in the same manner as described above, in the display device 200, the side light source 40 and the external light source 240 can be mixedly arranged. For example, a light source unit composed of a red light source 4nR and a green light source 4nG may be disposed as the side light source 40, and a blue external light source 240B may be disposed as the external light source 240. In this case, for example, in the field sequential control shown in FIG. 10, the period during which the side light source 40 lights the blue light source 4nB can be replaced with the lighting period of the blue external light source 240B.
Thus, by replacing one color of the side light sources 40 with the external light source 240, the arrangement interval of the side light sources 40 can be made finer, and a more detailed display is possible. For example, as shown in FIG. 6, when three of the red light source 41R, the green light source 41G, and the blue light source 41B are arranged in the arrangement direction of the display cells Cpq, the number of the color light sources is changed to two, thereby The width in the direction of the side light source 40 can be reduced.

Further, in the configuration in which a plurality of display panels 20 shown in FIG. 14 are stacked, incident light to one or a plurality of display panels 20 may be performed by the external light source 240.
The color of light incident from the side light source 40 and the color of light incident as the external light source 240 can be arbitrarily combined.

[Fifth Embodiment]
Next, a fifth embodiment will be described.
In the second embodiment, incident light or emitted light is natural light, but the fifth embodiment has a configuration using polarized light.

FIG. 16 is a diagram illustrating an example of the configuration of the display device according to the fifth embodiment. The same components as those of the display device 10 shown in FIG.
The display device 300 includes an image output unit 60, a synchronous drive unit 370, display panels 321, 322, panel drive circuits 331, 332, a side light source (G) 341, a side light source (R, B) 342, Light source driving circuits 351 and 352. In FIG. 16, the positions of the display panels 321 and 322 are illustrated as being shifted for the sake of explanation, but the respective display areas are overlapped.

  The display panel 321 has a configuration similar to that of the display panel 20 shown in FIG. 3, and a voltage corresponding to the color information is applied to the electrode corresponding to the display cell Cpq by the panel drive circuit 331, and the corresponding light modulation layer An electric field is generated in the region. In addition, light from the side light source (G) 341 enters the light modulation layer 80. In the example of FIG. 16, the side light source (G) 341 includes only a green light source that emits green light. A difference from the display panel 20 shown in FIG. 3 is that the display panel 321 is oriented in the orientation direction 381 shown in FIG. 16 by orientation treatment (for example, rubbing treatment or optical orientation treatment).

  The display panel 322 has a configuration similar to that of the display panel 321, and an electrode corresponding to the display cell Cpq is driven by the panel drive circuit 332, and an electric field is generated in the corresponding light modulation layer region. In addition, light from the side light source (R, B) 342 enters the light modulation layer region. The side light sources (R, B) 342 include a red red light source (R) and a blue blue light source (B). Similar to the display panel 321, the display panel 322 is oriented in the orientation direction 382 shown in FIG. 16 by orientation treatment.

  The synchronous drive unit 370 acquires the image signal SRGB from the image output unit 60, and synchronously drives the panel drive circuit 331 and the light source drive circuit 351, and the panel drive circuit 332 and the light source drive circuit 352. Note that, in the target display cell Cpq, the synchronous driving unit 370 synchronizes the timing at which the light source driving circuit 351 enters the corresponding color light and the panel driving circuit 331 apply the voltage to the corresponding electrode. . The same applies to the panel drive circuit 332 and the light source drive circuit 352. On the other hand, the display panel 321 and the display panel 322 need only have timing of at least one image frame period. As in the case where the display panels 20 shown in FIG. 14 are stacked, it is not necessary to strictly match the timing between the display panels. Details will be described later.

Next, the orientation of the display panels 321 and 322 will be described.
In the example shown in FIG. 16, the alignment directions 381 and 382 are aligned in the horizontal direction of the light modulation layer 80. For example, the alignment directions 381 and 382 are aligned by an alignment process. In this case, the liquid crystalline monomer 81 of the light modulation layer 80 is aligned in the longitudinal direction of the streak structure along the alignment direction. When an electric field is applied in this state, the liquid crystal molecules 82 are easily tilted in the longitudinal direction of the streak structure, and the tilt direction of the liquid crystal molecules 82 is aligned in the alignment direction as a whole.
In the display panels 321 and 322 of the fifth embodiment, when the panel drive circuits 331 and 332 apply voltages to the electrodes and an electric field is generated in the light modulation layer region, the liquid crystal molecules 82 in the light modulation layer region are tilted. Orientation is aligned. Thereby, polarized light having a uniform direction is emitted from the light modulation layer region. In the example of FIG. 16, the alignment direction 381 of the display panel 321 and the alignment direction 382 of the display panel 322 are the same, and both the display panel 321 and the display panel 322 are in the same direction as the alignment direction. Polarized light is emitted.

Further, the light emitted from the display panel 322 on the back side is incident on the upper display panel 321. The light modulation layer 80 of the display panel 321 is also formed in the same alignment direction 381. If the incident light from the back surface is polarized in the same direction as the alignment direction, the incident light can pass through the light modulation layer 80. it can. Transmission is also effective when an electric field is generated in the light modulation layer 80.
In this manner, by using the polarized light, the display device 300 allows the observer on the display panel 321 side to visually recognize the light emitted from both the display panels 321 and 322 even when the display panels 321 and 322 are overlapped. can do.

  In the above configuration, the display panels 321 and 322 are oriented horizontally, but the present invention is not limited to this. There are two types of typical alignment modes, the horizontal direction and the vertical direction, and any alignment method may be used as long as the tilt direction of the liquid crystal molecules can be aligned when a voltage is applied to the electrodes. In the case of horizontal orientation, as shown in FIG. 16, the display panel 321 and the display panel 322 are subjected to orientation treatment, and the display panel 321 and the display panel 322 are laminated so that the orientation directions are the same. In the case of vertical alignment, for example, an alignment film capable of forming a pretilt, PVA (Patterned Vertical Alignment) for controlling the tilt direction by a fringe electric field of a fine electrode, and MVA (Multi-domain Vertical Alignment) for forming a resin tape pattern. Etc. are known.

Hereinafter, the display function of the display device 300 will be described.
In the display device 300, incident light is incident from the side surface from the side light source (R, B) 342 toward the light modulation layer 80 of the display panel 322. This incident light is natural light with no polarization. When a voltage is applied to the electrode corresponding to the display cell Cpq where the incident light is incident and an electric field is generated in the light modulation layer region of the display cell Cpq, the incident light is scattered. The scattered light is polarized in the streak direction of the liquid crystalline monomer 81 along the alignment direction, and is emitted from the display panel 322 as emitted light.

FIG. 17 is a diagram illustrating an example of an emission amount of polarized light according to the fifth embodiment.
In FIG. 17A, the emission amount of polarized light coincident with the streak direction is the emission amount of polarized light polarized in the streak direction of the liquid crystalline monomer 81 emitted from the display panels 321 and 322, that is, the direction coincident with the alignment direction. FIG. FIG. 17A shows that the amount of light emitted in the polarization direction that matches the alignment direction is large in the emitted light.
FIG. 17B shows the emission amount of polarized light perpendicular to the streak direction, which shows the exit amount of polarized light polarized in a direction perpendicular to the streak direction emitted from the display panels 321 and 322. FIG. 17B shows that the amount of light emitted in the polarization direction perpendicular to the alignment direction is small in the emitted light.

  Thus, the light emitted from the display panels 321 and 322 is polarized in the alignment direction. Note that light emitted from the display panel 322 on the back side is incident on the display panel 321 on the upper layer side. The operation of the upper display panel 321 at this time will be described.

  FIG. 18 is a diagram illustrating an example of the relationship between the transmittance according to the polarization direction of the light incident from the back surface of the fifth embodiment and the driving voltage. S-polarized light indicates the transmittance when the polarization direction of incident light matches the streak direction (alignment direction) of the liquid crystalline monomer 81. P-polarized light indicates the transmittance when the polarization direction of incident light and the streak direction of the liquid crystalline monomer 81 are orthogonal to each other. The drive voltage is a voltage applied to an electrode that forms an electric field in the light modulation layer 80.

  As is clear from FIG. 18, in the state where the driving voltage is near 0 and no electric field is generated in the light modulation layer 80, the incident light whose polarization direction coincides with the alignment direction (S-polarized light) also has the polarization direction in the alignment direction. Incident light (P-polarized light) orthogonal to the light passes through the light modulation layer 80 and is emitted from the display panels 321 and 322. When a driving voltage is applied to the electrode and the light modulation layer 80 is in a scattering state, incident light (P-polarized light) whose polarization direction is orthogonal to the alignment direction is scattered by the light modulation layer 80 and hardly transmitted. On the other hand, incident light (S-polarized light) whose polarization direction coincides with the alignment direction is not scattered in the light modulation layer 80 and passes through the light modulation layer 80.

  Next, display control in the display device 300 having such a configuration will be described. In the display device 100 according to the third embodiment shown in FIG. 14, in the stacked display panels 20R, 20G, and 20B, the light emitted from the lower display panels 20B and 20G is transmitted through the upper display panel 20R. Although it is necessary to shift the scan lines of the panels 20R, 20G, and 20B, the display device 300 does not have to do so.

FIG. 19 is a diagram illustrating an example of display control of the display device according to the fifth embodiment. In FIG. 19, the panel drive circuits 331 and 332 and the light source drive circuits 351 and 352 are omitted.
In the display device 300, the panel driving circuit 331 and the side light source (G) 341, and the panel driving circuit 332 and the side light source (R, B) 342 are synchronously driven by the synchronous driving unit 370. Here, it is assumed that the scan lines of the upper display panel 321 and the lower display panel 322 are the same, and the case where the display cells Cpq of the respective display panels 321 and 322 overlapping in the vertical direction are driven in synchronization will be described.

  As an example, a case where the display cell C27a of the display panel 321 and the display cell C27b of the display panel 322 overlapping the display cell C27a are first driven in synchronization will be described. Based on the red component R27 of the image signal SRGB, red light is incident on the display cell C27b of the lower display panel 322 from the side light source (R, B) 342, and a voltage is applied to the electrode corresponding to the display cell C27b. The Thereby, the light modulation layer region of the display cell C27b scatters the incident red light and emits the red light Lr1. The red light Lr1 is polarized in the same polarization direction (X direction in FIG. 19) as the alignment direction 382 of the display panel 322. The red light Lr1 enters the display cell C27a of the upper display panel 321 from the back surface. In the example shown in FIG. 19, no voltage is applied to the electrode corresponding to the display cell C27a, and the incident red light Lr1 passes through the display cell C27a as it is. Thus, the red light Lr1 emitted from the lower display cell C27b is visually recognized by an observer.

  Next, a case where the display cell C32a of the display panel 321 and the display cell C32b of the display panel 322 overlapping the display cell C32a are driven in synchronization will be described. Blue light is incident on the display cell C32b of the lower display panel 322 from the side light source (R, B) 342, and a voltage is applied to the electrode corresponding to the display cell C32b. The light modulation layer region of the display cell C32b scatters incident blue light and emits blue light Lb1. The blue light Lb1 is polarized in the same polarization direction (X direction in FIG. 19) as the alignment direction 382 of the display panel 322. The blue light Lb1 enters the display cell C32a of the upper display panel 321 from the back surface. As shown in FIG. 18, since the light modulation layer 80 of the display device 300 transmits light polarized in the same direction as the alignment direction 381, the display cell C32a transmits blue light Lb1. Furthermore, in the example shown in FIG. 19, green light is incident on the display cell C32a from the side light source (G) 341, and a voltage is applied to the electrode corresponding to the display cell C32a. The display cell C32a scatters the incident green light and emits the green light Lg1. The green light Lg1 is also polarized in the same polarization direction as the alignment direction 381 (X direction in FIG. 19). Thus, the display cell C32a emits the transmitted blue light Lb1 of the display panel 322 and the green light Lg1 scattered from the incident light from the side light source (G) 341. Thus, the blue light Lb1 and the green light Lg1 are visually recognized by the observer.

  As described above, in the display device 300, the upper display panel 321 transmits the light from the lower display panel 322 whose polarization direction is incident from the back surface and matches the alignment direction, and is incident from the side light source (G) 341. It can scatter and emit light. Thus, an image of one image signal SRGB can be displayed on the stacked display panels 321 and 322. Since each color process can be shared by a plurality of display panels, the number of lines that can be driven can be increased. In addition, a sense of depth can be given to the display.

  Note that FIG. 19 shows a structure in which two display panels 321 and 322 are stacked. However, if display panels having the same structure as the display panels 321 and 322 are arranged with their orientation directions aligned, they are stacked. Any number of display panels may be used. As described with reference to FIGS. 3 and 4, the light modulation layer 80 included in the display device 300 has high transparency in a state where no electric field is generated. In addition, as shown in FIG. 18, since the polarization direction has a high transmittance even with respect to incident light from the same back surface as the alignment direction, high transparency can be obtained even when a plurality of display panels are stacked. Clear display can be realized.

In the display device 300, the side light sources 341 and 342 are used as the light sources of the light scattered by the display cell Cpq. However, an external light source 240 as shown in FIG. 15 may be used. Here, it is assumed that the external light source 240 is light that is not polarized. Also in the case of the external light source 240, the same light as the side light sources 341 and 342 is emitted from the display panels 321 and 322. That is, when a voltage is applied to the electrode corresponding to the corresponding display cell Cpq, the liquid crystal molecules 82 in the light modulation region of the display cell Cpq are inclined in alignment with the alignment direction. Thereby, the scattered light from which the incident light incident from the external light source 240 is scattered is also emitted as light polarized in the alignment direction.
Note that since the side light sources 341 and 342 and the external light source 240 can be driven in the same manner, the display device 300 may have a configuration in which the external light source 240 and the side light sources 341 and 342 are mixed.

In this way, by using polarized light, scattering and transmission can be simultaneously generated in the display cell Cpq of the display panel 321. That is, in a state where a voltage is applied to the electrode corresponding to the display cell Cpq, transmission and scattering of light incident from the front or back surface of the light modulation layer 80 can be switched according to the polarization plane of the incident light. In addition to the switching between the scattering state and the transmission state described with reference to FIGS. 2 to 15, display variations using polarized light can be performed to enrich the display variations.
In the following, an embodiment having a display panel in which alignment is performed and the tilt direction of liquid crystal molecules is aligned when a voltage is applied will be described with reference to FIGS. 20, 21, 22, and 23. Note that the lighting of the light source having the form of the side light source or the external light source and the voltage application to the electrode corresponding to the display cell Cpq are also driven synchronously in the configuration described below. For this reason, the description about the synchronous drive in the following structures is abbreviate | omitted.

[Sixth Embodiment]
Next, a sixth embodiment will be described.
In the fifth embodiment, a configuration in which a plurality of display panels having the same orientation direction are stacked is shown. However, in the sixth embodiment, a single display panel is configured. In the fifth embodiment, incident light incident from the side light sources 341 and 342 is natural light that is not polarized. However, the sixth embodiment has a configuration in which polarized light is incident.
FIG. 20 is a diagram illustrating an example of the configuration of the display device according to the sixth embodiment. (A) shows the case of projector projection, and (B) shows the case of projector non-projection.

  The display device 400 includes a display panel 420, a side light source 440, and a projector light source 441 that is an external light source. The display panel 420 includes the light modulation layer 80 and is processed so that the orientation direction 428 is the horizontal direction (X direction) in FIG. The side light source 440 receives light of a predetermined color from the side surface of the display panel 420.

  The projector light source 441 makes light incident on the light modulation layer 80 of the display panel 420 from the outside. By combining the light of the color incident from the side light source 440, an image of the image signal SRGB can be displayed. The projector light source 441 can emit light polarized in a selected polarization direction. In the example of FIG. 20, it is assumed that projector light source incident light PL1 polarized in a direction orthogonal to the horizontal alignment direction 428 and projector light source incident light PL3 polarized in a direction parallel to the alignment direction 428 can be selected.

  FIG. 20A shows a case where projector light source incident light PL1 polarized in a direction orthogonal to the orientation direction 428 is incident on the display panel 420 from the projector light source 441. FIG. In the display cell Cpq of the display panel 420 on which the projector light source incident light PL1 is incident, a voltage is applied to the electrodes, and an electric field is generated. The light modulation layer region corresponding to the display cell Cpq transmits light incident from the back surface when the light has a polarization direction parallel to the alignment direction 428. On the other hand, light having a polarization direction in a direction orthogonal to the alignment direction is scattered. Since the polarization direction of the projector light source incident light PL1 is orthogonal to the orientation direction, the light is scattered in the light modulation layer region. The scattered light PL2 is emitted to the outside and can be visually recognized by an observer. That is, light emitted from the projector light source 441 is projected on the display panel 420.

  On the other hand, FIG. 20B shows a case where projector light source incident light PL3 polarized in a direction parallel to the orientation direction 428 is incident on the display panel 420 from the projector light source 441. In the display cell Cpq of the display panel 420 to which the projector light source incident light PL3 is incident, a voltage is applied to the electrodes and an electric field is generated as in the case of FIG. In the light modulation layer region corresponding to the display cell Cpq, since the orientation direction 428 and the polarization direction of the incident projector light source incident light PL3 are parallel, this transmitted light PL4 is transmitted and transmitted through the light modulation layer region. That is, the light emitted from the projector light source 441 is not projected on the display panel 420.

  As described above, the display device 400 is formed such that the liquid crystal molecules 82 are aligned with each other when the light modulation layer 80 of the display panel 420 is aligned in a predetermined alignment direction and a voltage is applied to the electrodes. Therefore, in a state where a voltage is applied to the electrode of the target display cell Cpq, the transmission state and the display state can be switched by controlling the polarization direction of the projector light source 441 incident on the display cell Cpq. In the example of FIG. 20, when the incident light from the projector light source 441 is orthogonal to the orientation direction, the incident light is scattered and becomes scattered light PL2. If the incident light from the projector light source 441 is parallel to the alignment direction, the incident light is transmitted through the light modulation layer region of the display cell Cpq.

[Seventh Embodiment]
Next, a seventh embodiment will be described.
In the sixth embodiment, a configuration in which a single display panel is used and a projector light source is used has been described. In the seventh embodiment, a case in which a projector light source is used as a light source in a configuration having two display panels will be described. FIG. 21 is a diagram illustrating an example of the configuration of the display device according to the seventh embodiment. Note that the surface of the display panel 521 and the surface of the display panel 522 overlap with each other as in the fifth embodiment.

The display device 500 includes a display panel 521, a side light source (R) 541, a display panel 522, a side light source (B) 542, and a projector light source 543.
The display panel 521 includes the light modulation layer 80, and the alignment direction 528 is the horizontal direction (X direction) in FIG. The side light source (R) 541 is disposed on the side of the display panel 521.

The display panel 522 includes the light modulation layer 80, and the alignment direction 529 is a vertical direction (Y direction) orthogonal to the alignment direction 528 of the display panel 521. The side light source (B) 542 is a side of the display panel 522 and is arranged in a direction orthogonal to the side light source (R) 541.
Note that the length direction and the orientation direction of the side light source are preferably the same in terms of polarized light emission and light extraction efficiency. For this reason, the side light source (B) 542 is different in position from the side light source (R) 541.

  The projector light source 543 emits blue light Lb2 and green light Lg2 toward the display panel 521. In the example of FIG. 21, the blue light Lb2 emitted from the projector light source 543 is light polarized in the horizontal direction (X direction) in FIG. 21, and the polarization direction is parallel to the orientation direction 528 of the display panel 521. It is orthogonal to the orientation direction 529 of 522. The green light Lg2 is light that is polarized in the vertical direction (Y direction). The polarization direction is orthogonal to the alignment direction 528 of the display panel 521 and parallel to the alignment direction 529 of the display panel 522.

  In such a display panel 521 of the display device 500, the light incident on the display panel 521 from the side light source (R) 541 is scattered when a voltage is applied to the electrode of the corresponding display cell C39a, and red light is emitted. Lr2 is injected. The red light Lr2 is polarized in the same direction as the alignment direction 528. Since the polarization direction of the green light Lg2 emitted from the projector light source 543 toward the display panel 521 is orthogonal to the orientation direction 528, when a voltage is applied to the electrode of the corresponding display cell C26a, the green light Lg2 Scattered. On the other hand, since the polarization direction of the blue light Lb2 is the same as the orientation direction 528, the blue light Lb2 is transmitted through the display cell C23a and emitted to the display panel 522 even when a voltage is applied to the electrode of the corresponding display cell C23a.

The blue light Lb <b> 2 that has passed through the display panel 521 and entered the display panel 522 is scattered by the display panel 522 because the polarization direction is orthogonal to the orientation direction 529 of the display panel 522.
Depending on the polarization direction of the light emitted from the projector light source 543, the image is displayed on the upper display panel 521 like the display cell C26a, or is transmitted through the upper display panel 521 like the display cells C23a and C23b. It can be displayed on the display panel 522.

  Further, if the polarization direction of the light emitted from the projector light source 543 is switched, the blue light Lb2 is orthogonal to the orientation direction of the upper display panel 521, and the green light Lg2 is parallel to the orientation direction of the upper display panel 521, the display is performed. Is reversed. In this manner, the orientation direction 528 of the upper display panel 521 and the orientation direction 529 of the lower display panel 522 are orthogonal to each other, and the polarization direction of the light emitted from the projector light source 543 is switched, thereby displaying the display panel 521 and the display Different images can be displayed on the panel 522. The polarization direction of light emitted from the projector light source 543 can be realized by disposing an element that rotates the polarization direction between the projector light source 543 and the display panel 521. The projector light source 543 may have such a function.

  In the configuration of FIG. 21, the orientation direction of the upper display panel 521 and the orientation direction of the lower display panel 522 are orthogonal to each other. It is also possible to arrange a layer that changes.

FIG. 22 is a diagram illustrating a first modification of the display device according to the seventh embodiment. The same components as those in FIG. 21 are denoted by the same reference numerals, and description thereof is omitted.
The display device 501 has a configuration in which a display panel 521 and a display panel 523 are stacked with a λ / 2 phase difference plate 560 interposed therebetween. The surface of the display panel 521 and the surface of the display panel 523 overlap.

The display panel 521, the side light source (R) 541, and the projector light source 543 are the same as those in FIG.
The display panel 523 is different from the display panel 522 in that the orientation direction 530 is the same horizontal direction (X direction) as the orientation direction 528 of the display panel 521 and the position of the side light source (B) 544 is different. Similar to panel 522.

The λ / 2 phase difference plate 560 is disposed between the display panel 521 and the display panel 523, and changes the polarization plane of the transmitted light.
In the display device 501 having such a configuration, a case where blue light Lb3 and green light Lg3 having the same polarization direction as the orientation direction 528 of the display panel 521 are emitted from the projector light source 543 toward the display panel 521 will be described. .

  Since the polarization directions of the blue light Lb3 and the green light Lg3 are the same as the alignment direction 528 of the display panel 521, the blue light Lb3 and the green light Lg3 are transmitted through the display panel 521 and incident on the λ / 2 phase difference plate 560. To do. The blue light Lb3 and the green light Lg3 pass through the display cells C24a and C26a even when a voltage is applied, as well as when the voltage is not applied to the electrodes of the corresponding display cells C24a and C26a. Can do. The polarization planes of the blue light Lb3 and the green light Lg3 that have passed through the λ / 2 phase difference plate 560 change, and become polarization planes perpendicular to the orientation direction 530 of the display panel 523. In the display panel 523, when the voltage is applied to the electrodes of the corresponding display cells C24b and C26b, the blue light Lb3 and the green light Lg3 are scattered.

FIG. 23 is a diagram showing a case where projector light having a different polarization direction is incident on the configuration of FIG.
The blue light Lb4 is the same as that of the blue light Lb3 shown in FIG. The blue light Lb4 emitted from the projector light source 543 passes through the display panel 521, and after the polarization plane is switched in the λ / 2 phase difference plate 560, it is scattered in the display cell C24b of the display panel 523.

On the other hand, the green light Lg4 has a polarization direction orthogonal to the alignment direction 528 of the display panel 521, unlike FIG. For this reason, the green light Lg4 is scattered in the display cell C26a of the display panel 521.
Thereby, in the display panel 521, the green light Lg4 of the projector light source 543 and the red light Lr4 of the side light source (R) 541 are scattered by the corresponding display cells Cpq and are visually recognized by the observer. In the display panel 523, the blue light Lb4 of the projector light source 543 and the blue light of the side light source (B) 544 are scattered by the corresponding display cells Cpq and are visually recognized by an observer.
In this manner, by providing a layer for switching the polarization plane of incident light between the display panel 521 and the display panel 523, the display can be switched between the display panel 521 and the display panel 523.

  In addition, said structure is an example and this invention is not limited to this. It is possible to perform desired display by combining the number of display panels to be stacked and their orientation directions, the arrangement of layers for switching the polarization plane of incident light between the display panels, the polarization direction of the projector light source, and the like.

The above processing functions can be realized by a computer. In that case, a program describing the processing contents of the functions that the display device should have is provided. By executing the program on a computer, the above processing functions are realized on the computer. The program describing the processing contents can be recorded on a computer-readable recording medium. Examples of the computer-readable recording medium include a magnetic storage device, an optical disk, a magneto-optical recording medium, and a semiconductor memory. Examples of the magnetic storage device include a hard disk drive (HDD), a flexible disk (FD), and a magnetic tape. Optical disks include DVD (Digital Versatile Disc), DVD-RAM, CD (Compact Disc) -ROM, CD-R (Recordable) / RW (ReWritable), and the like. Magneto-optical recording media include MO (Magneto-Optical disk).
When distributing the program, for example, a portable recording medium such as a DVD or a CD-ROM in which the program is recorded is sold. It is also possible to store the program in a storage device of a server computer and transfer the program from the server computer to another computer via a network.

The computer that executes the program stores, for example, the program recorded on the portable recording medium or the program transferred from the server computer in its own storage device. Then, the computer reads the program from its own storage device and executes processing according to the program. The computer can also read the program directly from the portable recording medium and execute processing according to the program. In addition, each time a program is transferred from a server computer connected via a network, the computer can sequentially execute processing according to the received program.
In addition, at least a part of the above processing functions can be realized by an electronic circuit such as a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), or a PLD (Programmable Logic Device).

  In the scope of the idea of the present invention, those skilled in the art can conceive various changes and modifications, and it is understood that these changes and modifications also belong to the scope of the present invention. For example, those in which the person skilled in the art appropriately added, deleted, or changed the design of the above-described embodiments, or those in which the process was added, omitted, or changed the conditions are also included in the gist of the present invention. As long as it is provided, it is included in the scope of the present invention.

(1) One aspect of the disclosed invention is
A pair of transparent substrates spaced apart and opposed to each other;
A light modulation layer that is disposed between the pair of transparent substrates, has a predetermined refractive index anisotropy, and includes a plurality of light modulation elements having different responsiveness to an electric field generated by electrodes provided on the transparent substrate;
A light source that makes light of a predetermined color incident on the light modulation layer from a side surface of the light modulation layer;
Have
The light modulation layer transmits incident light incident from the light source when the electric field is not generated, and scatters the incident light when the electric field is generated and emits the incident light onto the transparent substrate.
It is a display device.

(2) One aspect of the disclosed invention is as follows:
The pair of transparent substrates, the outer surface side opposite to the light modulation layer side is open,
The light modulation layer has a transmission property of transmitting light in a penetrating direction that penetrates the transparent substrate and the light modulation layer when the electric field is not generated in the light modulation layer, and Transmitting light incident from one outer surface side in the penetrating direction and emitting the light to the other outer surface side of the pair of transparent substrates;
(1) The display device according to (1).

(3) One aspect of the disclosed invention is as follows:
The electrode generates the electric field in the display unit, with a divided region obtained by dividing the display region as a display unit,
The light source has a plurality of color light sources that operate independently and inject different colors of light into the display unit,
A drive unit that acquires color information of the display area and drives the lighting of the color light source according to the color information and voltage application to the electrodes synchronously for each display unit based on the color information. ,
The display device according to (1) or (2).

(4) One aspect of the disclosed invention is as follows:
The light source includes a first color light source that emits a first primary color, a second color light source that emits a second primary color, and a third color light source that emits a third primary color,
The drive unit turns on the first color light source and applies a voltage corresponding to the color component of the first primary color included in the color information to the electrode for each display unit during a period of one image display frame. The second color light source is turned on, a voltage corresponding to the color component of the second primary color included in the color information is applied to the electrode, and the third color light source is turned on and included in the color information. A voltage corresponding to the color component of the third primary color is applied to the electrode;
The display device according to (3).

(5) One aspect of the disclosed invention is
For each color component included in the color information, the driving unit
The color light source corresponding to the color component is turned on and light of the color component is incident on a planar region of the light modulation layer, and voltage application to the display unit electrodes is sequentially performed.
(3) or (4).

(6) One aspect of the disclosed invention is
For each display unit group including the display units arranged along the incident direction in which the light from the color light source is incident,
The color light source corresponding to the color component included in the color information is turned on so that the light of the color component is incident on the area of the display unit group of the light modulation layer, and the display unit included in the display unit group Sequentially apply voltage to the electrodes
(3) or (4).

(7) One aspect of the disclosed invention is as follows:
The drive unit turns on or turns off the light source corresponding to the second display unit group adjacent to the first display unit group to be driven in the same color as the first display unit group;
The display device according to (6).

(8) One aspect of the disclosed invention is
The electrodes include a plurality of first electrodes having a strip shape extending in one direction in the plane of one transparent substrate of the pair of transparent substrates, and the plane in the plane of the other transparent substrate of the pair of transparent substrates. A plurality of second electrodes having a strip shape extending in a direction intersecting with a direction in which the first electrode extends, and the display unit is provided at a portion where the first electrode and the second electrode intersect Formed,
The drive unit performs simple matrix drive control for sequentially driving the first electrode and the second electrode.
(3) The display device according to any one of (7).

(9) One aspect of the disclosed invention is
Between the light source and the light modulation layer, an incident light diffusion prevention unit that prevents diffusion of the light of the light source incident on the light modulation layer is provided.
(1) It is a display device in any one of (8).

(10) One aspect of the disclosed invention is
The transparent substrate includes an in-layer light diffusion prevention unit that prevents diffusion of light from the light source that travels in the light modulation layer.
The in-layer light diffusion preventing unit is provided along a traveling direction of light of the light source incident on the light modulation layer.
(1) It is a display device in any one of (9).

(11) One aspect of the disclosed invention is
A first display panel and a second display panel having the pair of transparent substrates, the light modulation layer, and the light source,
The driving unit includes: a position of a first scan line that sequentially applies a voltage to the electrodes in the first display panel; and a second scan line that sequentially applies a voltage to the electrodes driven in the second display panel. The first display panel and the second display panel are driven synchronously while shifting the position.
(3) It is a display device in any one of (9).

(12) One aspect of the disclosed invention is as follows:
A pair of transparent substrates spaced apart and opposed to each other;
A light modulation layer that is disposed between the pair of transparent substrates, has a predetermined refractive index anisotropy, and includes a plurality of light modulation elements having different responsiveness to an electric field generated by electrodes provided on the transparent substrate;
An external light source that makes light of a predetermined color incident on the light modulation layer from the outside of the transparent substrate;
A drive unit that acquires color information of a display area, and based on the color information, synchronously drives lighting of the external light source and voltage application to the electrodes;
Have
The light modulation layer transmits incident light incident from the light source when the electric field is not generated, and scatters the incident light when the electric field is generated and emits the incident light onto the transparent substrate.
It is a display device.

(13) One aspect of the disclosed invention is
A light source that makes light of a predetermined color incident on the light modulation layer from a side surface of the light modulation layer;
The driving unit synchronously drives lighting of the external light source, lighting of the light source, and voltage application to the electrodes based on the color information.
(12) The display device according to (12).

(14) One aspect of the disclosed invention is as follows:
A transparent substrate comprising a pair of transparent substrates disposed opposite to each other, and a first light modulation element and a second light modulation element disposed between the pair of transparent substrates and having a predetermined refractive index anisotropy, Responsiveness of the second light modulation element to the electric field generated by the electrode provided on the second electrode is formed to be relatively higher than the responsiveness of the first light modulation element to the electric field, and the second at the time of response to the electric field. A first display panel and a second display panel each having a light modulation layer in which the inclination directions of the light modulation elements are aligned, respectively, the inclination direction of the first display panel, and the second display panel Are arranged in the same direction as the tilt direction,
The first display panel and the second display panel are:
When the electric field is not generated, the incident light is transmitted,
When the electric field is generated, the incident light component having the same polarization direction and the same polarization direction is transmitted, and the incident light component having a different polarization direction and the polarization direction is scattered to be polarized in a direction according to the inclination direction. Emitting the polarized light to the transparent substrate,
It is a display device.

(15) One aspect of the disclosed invention is as follows:
The first display panel has a light source that makes light of a predetermined color incident on the light modulation layer from a side surface of the light modulation layer, and is disposed on the back surface of the second display panel.
(14) The display device according to (14).

(16) One aspect of the disclosed invention is as follows:
Between the first display panel and the second display panel, there is a retardation plate that changes the polarization plane of the incident light.
(14) The display device according to (15).

(17) One aspect of the disclosed invention is
An external light source that outputs polarized light polarized in a predetermined polarization direction;
The driving unit synchronously drives lighting of the external light source, lighting of the light source, and voltage application to the electrodes based on color information.
(14) The display device according to any one of (16).

(18) One aspect of the disclosed invention is as follows:
Between the external light source and the modulation layer, provided with an element for rotating the polarization direction of the light emitted from the external light source,
(17) The display device according to (17).

(19) One aspect of the disclosed invention is as follows:
A pair of transparent substrates spaced apart and opposed to each other;
The second light with respect to an electric field generated by an electrode provided on the transparent substrate, the first light modulation device and the second light modulation device having a predetermined refractive index anisotropy disposed between the pair of transparent substrates. A light modulation layer in which the response of the modulation element is formed to be relatively higher than the response of the first light modulation element to the electric field, and the tilt direction of the second light modulation element at the time of the response to the electric field is aligned; ,
Have
The light modulation layer transmits the incident light when the electric field is not generated,
When the electric field is generated, the incident light component having the same polarization direction and the same polarization direction is transmitted, and the incident light component having a different polarization direction and the polarization direction is scattered to be polarized in a direction according to the inclination direction. Emitting the polarized light to the transparent substrate,
It is a display device.

(20) One aspect of the disclosed invention is as follows:
The light modulation layer is a layer in which liquid crystal molecules are dispersed in a polymer material.
(1) It is a display apparatus as described in (19).

  DESCRIPTION OF SYMBOLS 1 ... Display apparatus 2, 2a, 2b ... Transparent substrate, 4 ... Light modulation layer, 4a ... 1st light modulation element, 4b ... 2nd light modulation element, 8 ... Light source, 10 ... display device, 20 ... display panel, 22 ... lower transparent substrate, 23 ... upper transparent substrate, 24 ... light guide pattern, 25 ... cylindrical pattern, 30. ..Panel drive circuit 31 ... Lower electrode 32 ... Upper electrode 40 ... Side light source 41,42,43,44,45,46,47,48,49 ... Light source unit 50 ... Light source drive circuit, 60 ... Image output unit, 70 ... Synchronous drive unit, 71 ... Timing generation unit, 72 ... Display cell drive signal generation unit, 73 ... Light source drive Signal generation unit, 80 ... light modulation layer, 81 ... liquid crystal Monomer, 82 ... liquid crystal molecules, 240 ... external light source, 250 ... external light source driving unit

Claims (11)

A pair of transparent substrates spaced apart and opposed to each other;
A light modulation layer that is disposed between the pair of transparent substrates, has a predetermined refractive index anisotropy, and includes a plurality of light modulation elements having different responsiveness to an electric field generated by electrodes provided on the transparent substrate;
A light source that makes light of a predetermined color incident on the light modulation layer from a side surface of the light modulation layer;
Have
The light modulation layer transmits incident light incident from the light source when the electric field is not generated, and scatters the incident light when the electric field is generated and emits the incident light onto the transparent substrate.
Display device. The pair of transparent substrates, the outer surface side opposite to the light modulation layer side is open,
The light modulation layer has a transmission property of transmitting light in a penetrating direction that penetrates the transparent substrate and the light modulation layer when the electric field is not generated in the light modulation layer, and Transmitting light incident from one outer surface side in the penetrating direction and emitting the light to the other outer surface side of the pair of transparent substrates;
The display device according to claim 1. The electrode generates the electric field in the display unit, with a divided region obtained by dividing the display region as a display unit,
The light source has a plurality of color light sources that operate independently and inject different colors of light into the display unit,
A drive unit that acquires color information of the display area and drives the lighting of the color light source according to the color information and voltage application to the electrodes synchronously for each display unit based on the color information. ,
The display device according to claim 1. For each color component included in the color information, the driving unit
The color light source corresponding to the color component is turned on and light of the color component is incident on a planar region of the light modulation layer, and voltage application to the display unit electrodes is sequentially performed.
The display device according to claim 3. For each display unit group including the display units arranged along the incident direction in which the light from the color light source is incident,
The color light source corresponding to the color component included in the color information is turned on so that the light of the color component is incident on the area of the display unit group of the light modulation layer, and the display unit included in the display unit group Sequentially apply voltage to the electrodes
The display device according to claim 3. A pair of transparent substrates spaced apart and opposed to each other;
A light modulation layer that is disposed between the pair of transparent substrates, has a predetermined refractive index anisotropy, and includes a plurality of light modulation elements having different responsiveness to an electric field generated by electrodes provided on the transparent substrate;
An external light source that makes light of a predetermined color incident on the light modulation layer from the outside of the transparent substrate;
A drive unit that acquires color information of a display area, and based on the color information, synchronously drives lighting of the external light source and voltage application to the electrodes;
Have
The light modulation layer transmits incident light incident from the light source when the electric field is not generated, and scatters the incident light when the electric field is generated and emits the incident light onto the transparent substrate.
Display device. A light source that makes light of a predetermined color incident on the light modulation layer from a side surface of the light modulation layer;
The driving unit synchronously drives lighting of the external light source, lighting of the light source, and voltage application to the electrodes based on the color information.
The display device according to claim 6. A transparent substrate comprising a pair of transparent substrates disposed opposite to each other, and a first light modulation element and a second light modulation element disposed between the pair of transparent substrates and having a predetermined refractive index anisotropy, Responsiveness of the second light modulation element to the electric field generated by the electrode provided on the second electrode is formed to be relatively higher than the responsiveness of the first light modulation element to the electric field, and the second at the time of response to the electric field. A first display panel and a second display panel each having a light modulation layer in which the inclination directions of the light modulation elements are aligned, respectively, the inclination direction of the first display panel, and the second display panel Are arranged in the same direction as the tilt direction,
The first display panel and the second display panel are:
When the electric field is not generated, the incident light is transmitted,
When the electric field is generated, the incident light component having the same polarization direction and the same polarization direction is transmitted, and the incident light component having a different polarization direction and the polarization direction is scattered to be polarized in a direction according to the inclination direction. Emitting the polarized light to the transparent substrate,
Display device. The first display panel has a light source that makes light of a predetermined color incident on the light modulation layer from a side surface of the light modulation layer, and is disposed on the back surface of the second display panel.
The display device according to claim 8. Between the first display panel and the second display panel, there is a retardation plate that changes the polarization plane of the incident light.
The display device according to claim 8 or 9. A pair of transparent substrates spaced apart and opposed to each other;
The second light with respect to an electric field generated by an electrode provided on the transparent substrate, the first light modulation device and the second light modulation device having a predetermined refractive index anisotropy disposed between the pair of transparent substrates. A light modulation layer in which the response of the modulation element is formed to be relatively higher than the response of the first light modulation element to the electric field, and the tilt direction of the second light modulation element at the time of the response to the electric field is aligned; ,
Have
The light modulation layer transmits the incident light when the electric field is not generated,
When the electric field is generated, the incident light component having the same polarization direction and the same polarization direction is transmitted, and the incident light component having a different polarization direction and the polarization direction is scattered to be polarized in a direction according to the inclination direction. Emitting the polarized light to the transparent substrate,
Display device.

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